1. Field of the Invention
This invention relates to the field of analytic devices, systems and methods, especially those performed on tissue specimens and body fluids deposited on glass slides, or contained between rigid planar glass or plastic sheets. More particularly, this invention addresses the introduction of reagent fluids to generate a reaction of interest with the specimen mounted or entrained within the cavity defined by parallel rigid optically transmissible plates.
Slide-based diagnostic procedures constitute the oldest class of in vitro analysis of specimens of clinical interest. The mounting of tissue or other sample on a planar glass surface for microscopic examination dates to the dawn of modern pathology. The enhancement of contrast in specimens has been accomplished by using staining chemicals which delineate the structure of the specimen. These cytology and histology stains have in the past been inexpensive chemicals which were applied to the specimen by total immersion of the slide. Wastage of stain fluid was not a consideration in these procedures.
Recent developments in biotechnology have yielded a class of staining reagents which are derived from recombinant DNA or monoclonal antibody production procedures. Unlike traditional cytology and histology reagents these are extremely costly and cannot be applied by immersion procedures. Conventional slide staining equipment cannot economically apply these reagents to slide-based specimens. The development of these extremely effective but costly reagents has defined a requirement for precision deposition of reagent materials on slide mounted or entrained specimens only in areas of procedural effectiveness. Currently this is accomplished manually. The economical and technical need for an automated means of accomplishing precision reagent deposition on specimens of this class is the stimulus for this invention.
2. Prior Art
Prior art citations describing parallel rigid plate specimen mounting or retention, and introduction of reactant materials include the following examples as an overview of the patent literature. Chediak (U.S. Pat. No. 2,561,339) describes a slide form comprising a separated parallel glass and plastic arrangement designed to receive specimens in discrete retention areas, and features a sliding cover plate. Wallace (U.S. Pat. No. 3,656,833) teaches a parallel plate laboratory slide apparatus employing a plurality of blind apertures molded into a plastic member mounted parallel to a glass substrate. The intent of this arrangement is to retain specimen and reactant. Meunier (U.S. Pat. No. 4,237,234) describes a radially arranged series of parallel plates between which specimen materials are placed. The device is representative of a class of laboratory test implements which employ centrifugal force to distribute or remove reactive agents from areas of interest. Cottingham (U.S. Pat. No. 4,596,695) discloses a slide-like reaction chamber which entrains particulate reagents between parallel plates, and introduces the reactants by means of capillary action. Lilja (U.S. Pat. No. 4,088,448) a planar cavity molded to define parallel walls in which a reactant fluid combination is introduced. Additionally, Meserol U.S. Pat. No. 4,400,353, issued to the inventor of this application, teaches a coplanar device in which the particulate reactant is caused to move and mix under rotation.
In the scientific literature, Badley, et al. reported a planar capillary device (Phil. Trans. Royal Soc. London. B 316, 143-160). Kronick and Little report a quartz plate planar cell assembly in Journal of Immunological Methods 8 (1975) 235-240. None of the cited prior art references employ a means of precision deposition under control of automata. There exists a need for a slide implement compatible with laboratory specimen forms such as sections or swab depositions, processed, prepared, and evaluated by an automated system capable of efficient reagent deposition in accordance with modern protocols and reagent formations.